feat: add setup-llama.ps1 script to automate downloading and installing llama.cpp backends

scripts/setup-llama.ps1

@@ -7,6 +7,29 @@ $appDir = Join-Path $rootDir "app"
 $toolsDir = Join-Path $appDir "tools"
 $llmRoot = Join-Path $appDir "llm-backend\win"
 
+function Enable-Tls12 {
+    try {
+        $tls12 = [Enum]::ToObject([Net.SecurityProtocolType], 3072)
+        [Net.ServicePointManager]::SecurityProtocol =
+            [Net.ServicePointManager]::SecurityProtocol -bor $tls12
+    } catch {
+        throw "TLS 1.2 could not be enabled: $($_.Exception.Message)"
+    }
+}
+
+function Format-Bytes {
+    param([long]$b)
+    if ($b -gt 1GB) { return "{0:N2} GB" -f ($b / 1GB) }
+    if ($b -gt 1MB) { return "{0:N1} MB" -f ($b / 1MB) }
+    return "{0:N0} KB" -f ($b / 1KB)
+}
+
+function Format-Speed {
+    param([double]$bps)
+    if ($bps -gt 1MB) { return "{0:N1} MB/s" -f ($bps / 1MB) }
+    return "{0:N0} KB/s" -f ($bps / 1KB)
+}
+
 function Install-LlamaArchive {
     param([string]$Variant, [string]$AssetName)
 
@@ -23,8 +46,62 @@ function Install-LlamaArchive {
 
     New-Item -ItemType Directory -Force -Path $toolsDir, $dest | Out-Null
     Remove-Item $archive, $extract -Recurse -Force -ErrorAction SilentlyContinue
+
     Write-Host "   >>  Downloading llama.cpp $Variant backend ($Release)..."
-    Invoke-WebRequest -UseBasicParsing -Headers @{ "User-Agent" = "Local-AI-Studio" } -Uri $url -OutFile $archive
+    
+    $barWidth  = 48
+    $lastBytes = [long]0
+    $lastTime  = [DateTime]::Now
+
+    try {
+        Enable-Tls12
+        $req    = [System.Net.HttpWebRequest]::Create($url)
+        $req.UserAgent = "Mozilla/5.0"
+        $resp   = $req.GetResponse()
+        $total  = [long]$resp.ContentLength
+        $stream = $resp.GetResponseStream()
+        $out    = [System.IO.File]::Create($archive)
+        $buf    = New-Object byte[] 65536
+        $done   = [long]0
+
+        while ($true) {
+            $read = $stream.Read($buf, 0, $buf.Length)
+            if ($read -le 0) { break }
+            $out.Write($buf, 0, $read)
+            $done += $read
+
+            $now     = [DateTime]::Now
+            $elapsed = ($now - $lastTime).TotalSeconds
+            if ($elapsed -ge 0.35) {
+                $speed     = ($done - $lastBytes) / $elapsed
+                $lastBytes = $done
+                $lastTime  = $now
+                $pct  = if ($total -gt 0) { [int](($done / $total) * 100) } else { 0 }
+                $fill = [int](($pct / 100) * $barWidth)
+                $bar  = ("#" * $fill) + ("-" * ($barWidth - $fill))
+
+                $eta = ""
+                if ($speed -gt 0 -and $total -gt 0) {
+                    $rem = [int](($total - $done) / $speed)
+                    $eta = "  ETA $([int]($rem/60))m$($rem%60)s"
+                }
+
+                $dl  = Format-Bytes $done
+                $tot = if ($total -gt 0) { " / " + (Format-Bytes $total) } else { "" }
+                $spd = Format-Speed $speed
+                Write-Host -NoNewline "`r      [$bar] $pct%  $dl$tot  $spd$eta   "
+            }
+        }
+
+        $out.Close(); $stream.Close()
+        Write-Host "`r      [$("#" * $barWidth)] 100%  $(Format-Bytes $done)  Done!                         " -ForegroundColor Green
+        Write-Host ""
+    } catch {
+        Write-Host ""
+        throw "Download failed: $_"
+    }
+
+    Write-Host "   >>  Extracting llama.cpp $Variant backend..."
     Expand-Archive -Path $archive -DestinationPath $extract -Force
 
     Get-ChildItem $extract -Recurse -File | ForEach-Object {